The process of vaccination involves injecting a small amount of deactivated or dead virus into the body so that the body’s natural defenses can strengthen an immunity to it. It’s kind of like getting the other team’s playbook before the big game. These deactivated forms of viruses are used to prevent an extensive list of diseases, including pneumonia, whooping cough, influenza, and tuberculosis–preventable diseases that kill millions of people every year.

Of course, in a very small number of cases, that amount of deactivated virus can cause sickness, but the benefits far outweigh the risks.

The concerns of anti-vaxxers are many and range from the absurd, like claims that vaccines lead to an increased risk for autism (which has been proven falsemany times) to the seemingly reasonable worry that these diseases simply don’t pose enough of a threat–nor do we understand enough about the chemicals in the vaccine themselves–to deliberately expose children to them. Of course, no one wants to expose their children to something that could possibly hurt them, but here’s why anti-vaxxers are doing more harm than they might think:

A child, without the vaccine, will become sick when exposed to measles. Source: Julian Harneis

Many anti-vaxxers take their cues from inaccurate and unscientific sites like this popular one called VaxTruth.org, where Guest Author Dawn Babcock Papple (capitalization hers) proceeds to show readers screenshots of her computer’s calculator to prove, unequivocally, that she’s done the math on the measles vaccine and it’s a bunch of hokey. Papple cites her own graphs created in Microsoft Word and this apocryphal piece of medical science from 1936.

Watch this short clip on herd immunity, which simply explains why your unvaccinated child is a threat to everyone, even if the people he or she encounters are vaccinated:

Famed bioethicist Albert Caplan sums things up in his tough-as-nails, uncompromising way: “It is neglect to expose your child to vaccine-preventable disease. (…) It is selfish to expose my kids to disease.”

All other variables being constant: the presence and proper use of vaccines leads to a drop in mortality. More injections means fewer funerals, and it might just be someone else’s child that you are protecting.